US-national · general · 2020-11-03

2020 US Presidential (Popular Vote)

Solid D · 100%demopre-registered 2026-04-21 · commit 20afa53
Final forecast · calibrated
biden52.1%
80% interval: [51.9%, 52.4%] · P(win) 100%
trump47.9%
80% interval: [47.6%, 48.1%] · P(win) 0%
Margin: p50 4.2pp · 80% interval [3.8, 4.8]pp · 100 Monte Carlo trials
Per-engine breakdown
fundamentalscontribution 19% · confidence 30%
biden 50.0%trump 50.0%
  • · pregame prior: biden=53.0%, trump=47.0%
  • · incumbent trump: +3.0pp
pollingcontribution 44% · confidence 51%
biden 53.3%trump 46.7%
  • · 5/6 polls used (weight=2.12)
  • · house-effect correction applied (R→trump, D→biden)
  • · weighted shares: biden=53.3%, trump=46.7%
syntheticcontribution 22% · confidence 35%
biden 52.3%trump 47.7%
  • · synthetic electorate (5000 voters) final shares: biden=52.3%, trump=47.7%
eventcontribution 15% · confidence 40%
biden 53.6%trump 46.4%
  • · 3 events in last 14 days contributed to the shift
ensemble shrinkage 15% · race-type weights: polling 35% · fundamentals 25% · synthetic 25% · event 15%
How OMEN saw this race over time
HorizonCalibrated sharespollsevents
T−90biden 49.9% · trump 50.1%00
T−60biden 51.5% · trump 48.5%12
T−30biden 52.0% · trump 48.0%24
T−14biden 52.5% · trump 47.5%34
T−7biden 52.1% · trump 47.9%46
T−0biden 52.1% · trump 47.9%68
Population

Voters sampled from hand-authored segment mix. 5,000 simulated voters, seed omen_pol_v0.

partisan base
35.0%
swing
15.0%
low info
25.0%
demographic bloc
15.0%
cross pressured
10.0%
Resolution
winner correct
biden 51.3%trump 46.9%turnout 67%
Share err
0.90pp
Margin err
0.11pp
Brier (winner)
0.229